Overpriced False Line Speed packages

I signed up for Webafricas 50Mbps Fibre line at R999 pm and am only receiving 20 to 23Mbps speed, I have called thier call center on several occasions to resolve with no success. A manager promised to call, no call revived to date, tried their chat line as well no success. I asked that they send out a Vumatel technician to resolve they advised they are unable to.